Substrate processing method

Abstract

To provide a technique that can effectively reduce the rate of collapse of a substrate pattern.SOLUTION: A substrate processing method includes a holding step, a liquid supplying step, a drying liquid supplying step, and a drying step. In the holding step, a substrate having a first main surface on which a pattern is formed and a second main surface on the opposite side to the first main surface is held. In the liquid supplying step, a processing liquid is supplied to the first main surface of the substrate. In the drying liquid supplying step, after the liquid supplying step, the drying liquid is supplied to the first main surface of the substrate at a flow rate at which the temperature of the first main surface of the substrate is less than the boiling point bp of the drying liquid while at least a part of the second main surface of the substrate is heated to a temperature equal to or higher than the boiling point bp of the drying liquid. In the drying step, after the drying liquid supplying step, the substrate is dried.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a method for processing a substrate. [Background technology]

[0002] Conventionally, single-wafer substrate processing apparatuses for processing substrates have been disclosed (for example, Patent Document 1). In Patent Document 1, the substrate processing apparatus supplies a rinsing liquid to the substrate, then supplies isopropyl alcohol, which has a lower surface tension than the rinsing liquid, to the substrate, and then dries the substrate. This prevents the pattern on the substrate from collapsing during drying. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-23182 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 does not consider the temperature of isopropyl alcohol, and therefore cannot effectively reduce the rate of pattern collapse.

[0005] Therefore, an object of the present disclosure is to provide a technique that can effectively reduce the rate of collapse of a pattern on a substrate. [Means for solving the problem]

[0006] A first aspect is a substrate processing method comprising: a holding step of holding a substrate having a first main surface on which a pattern is formed and a second main surface opposite to the first main surface; a liquid supplying step of supplying a processing liquid to the first main surface of the substrate; after the liquid supplying step, a drying liquid supplying step of supplying the drying liquid to the first main surface of the substrate at a flow rate such that the temperature of the first main surface of the substrate is below the boiling point of the drying liquid while heating at least a portion of the second main surface of the substrate to a temperature equal to or higher than the boiling point of the drying liquid; and after the drying liquid supplying step, a drying step of drying the substrate.

[0007] A second aspect is the substrate processing method according to the first aspect, wherein in the drying liquid supplying step, a heat medium having a boiling point equal to or higher than the drying liquid is supplied to the second main surface of the substrate.

[0008] A third aspect is the substrate processing method according to the first or second aspect, wherein in the drying liquid supplying step, a peripheral portion of the second main surface of the substrate is heated to a boiling point of the drying liquid or higher.

[0009] A fourth aspect is a substrate processing method according to the third aspect, wherein, in the drying liquid supplying step, a central portion of the second main surface of the substrate is heated to a temperature lower than a temperature of the peripheral portion of the second main surface.

[0010] A fifth aspect is a substrate processing method according to the fourth aspect, wherein, in the drying liquid supply process, a heat medium at a first medium temperature is supplied to the peripheral portion of the second main surface of the substrate, and a heat medium at a second medium temperature lower than the first medium temperature is supplied to the central portion of the second main surface of the substrate.

[0011] A sixth aspect is a substrate processing method according to any one of the first to fifth aspects, wherein, in the drying liquid supply step, the second main surface of the substrate is heated only during a latter part of a drying liquid supply time during which the drying liquid is supplied.

[0012] A seventh aspect is a substrate processing method according to any one of the first to sixth aspects, wherein, in the drying liquid supplying process, the temperature of the first main surface of the substrate is equal to or higher than 60 degrees Celsius and lower than the boiling point of the drying liquid. Effect of the Invention

[0013] According to the first aspect, in the drying liquid supplying step, while at least a part of the second main surface of the substrate is heated to the boiling point of the drying liquid or higher, the drying liquid is supplied at a flow rate that makes the temperature of the first main surface of the substrate lower than the boiling point. Therefore, while bringing the temperature of the first main surface of the substrate closer to the boiling point of the drying liquid, the boiling of the drying liquid can be more reliably suppressed, and the adhesion of particles can be suppressed. Furthermore, since the temperature of the first main surface is closer to the boiling point, in the subsequent drying step, the drying liquid can be evaporated in a shorter time with a lower surface tension. Therefore, the collapse rate of the pattern can be effectively reduced.

[0014] According to the second aspect, the temperature of at least a part of the second main surface of the substrate can be made equal to or higher than the boiling point of the drying liquid with a simple configuration.

[0015] According to the third aspect, the pattern collapse rate in the peripheral portion can be reduced. Since the pattern collapse rate in the peripheral portion tends to be higher than the pattern collapse rate in the central portion, the pattern collapse rate can be reduced over the entire first main surface of the substrate.

[0016] According to the fourth aspect, while reducing power consumption, it is possible to reduce the collapse rate of the pattern in the central portion of the first main surface of the substrate, thereby further reducing the collapse rate of the entire pattern.

[0017] According to the fifth aspect, the collapse rate of the pattern over the entire first main surface of the substrate can be effectively reduced with a simple configuration.

[0018] According to the sixth aspect, it is possible to reduce power consumption.

[0019] According to the seventh aspect, the rate of pattern collapse can be effectively reduced. [Brief description of the drawings]

[0020] [Figure 1] 1 is a plan view illustrating an example of a configuration of a substrate processing apparatus. [Diagram 2] 2 is a block diagram illustrating an example of an internal configuration of a control unit. FIG. [Diagram 3] FIG. 2 is a vertical cross-sectional view illustrating an example of the configuration of a processing unit according to the first embodiment. [Figure 4] 13 is a flowchart showing an example of an operation of a processing unit. [Diagram 5] 11A and 11B are diagrams each showing an example of a processing unit in a drying liquid supplying step; [Figure 6] 5A to 5C are diagrams each showing a timing chart of a processing unit, and a schematic diagram showing an example of a change in temperature of a heat medium over time and a change in temperature of a first main surface of a substrate over time. [Figure 7] FIG. 11 is a diagram illustrating roughly a first example of a substrate heating part according to a second embodiment. [Figure 8] FIG. 11 is a diagram illustrating a first example of the configuration of a portion of a processing unit according to a second embodiment. [Figure 9] FIG. 11 is a diagram illustrating a second example of a substrate heating section according to a second embodiment. [Figure 10] FIG. 13 is a diagram illustrating a second example of the configuration of a portion of the processing unit according to the second embodiment. [Figure 11] FIG. 13 is a diagram illustrating an example of a timing chart of a processing unit according to a third embodiment. [Figure 12] 13 is a flowchart showing a first example of the operation of the processing unit according to the fourth embodiment. [Figure 13] 13 is a flowchart showing a second example of the operation of the processing unit according to the fourth embodiment. [Figure 14] FIG. 13 is a diagram illustrating an example of the configuration of a processing unit according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the drawings, the dimensions and numbers of each part are exaggerated or simplified as necessary for the purpose of easy understanding. Parts having similar configurations and functions are given the same reference numerals, and duplicated explanations will be omitted in the following description.

[0022] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions thereof may be omitted to avoid duplication.

[0023] In addition, in the description below, even if ordinal numbers such as "first" or "second" are used, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and are not limited to the ordering that may result from these ordinal numbers.

[0024] When an expression indicating a relative or absolute positional relationship (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) is used, the expression not only strictly indicates the positional relationship, but also indicates a state in which the relative positional relationship is displaced with respect to angle or distance within a range in which a tolerance or similar function is obtained, unless otherwise specified. When an expression indicating an equal state (e.g., "same," "equal," "homogeneous," etc.) is used, the expression not only strictly indicates a quantitatively equal state, but also indicates a state in which a difference exists within a range in which a tolerance or similar function is obtained, unless otherwise specified. When an expression indicating a shape (e.g., "square shape" or "cylindrical shape," etc.) is used, the expression not only strictly indicates the shape geometrically, but also indicates a shape having, for example, unevenness or chamfering within a range in which a similar effect is obtained, unless otherwise specified. When an expression "comprises," "has," "includes," "includes," or "has" a component is used, the expression is not an exclusive expression that excludes the presence of other components. When the phrase "at least one of A, B, and C" is used, the phrase includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0025] First Embodiment <Overall configuration of substrate processing apparatus> 1 is a plan view illustrating a schematic configuration of a substrate processing apparatus 100. The substrate processing apparatus 100 is a single-wafer processing apparatus that processes substrates W one by one.

[0026] The substrate W is, for example, a semiconductor wafer, a substrate for a liquid crystal display, a substrate for an organic EL (Electroluminescence), a substrate for an FPD (Flat Panel Display), a substrate for an optical display, a substrate for a magnetic disk, a substrate for an optical disk, a substrate for a magneto-optical disk, a substrate for a photomask, or a substrate for a solar cell. The substrate W has a thin flat plate shape having a first main surface Wa and a second main surface Wb. The second main surface Wb is the surface opposite to the first main surface Wa. In the following, the substrate W is assumed to be a semiconductor wafer. The substrate W has, for example, a disk shape. The diameter of the substrate W is, for example, about 300 mm, and the thickness of the substrate W is, for example, about 0.5 mm or more and about 3 mm or less. A pattern is formed on the main surface of the substrate W. The pattern here includes, for example, at least one of a wiring pattern, an electrode pattern, a semiconductor pattern, and an insulating pattern. The aspect ratio of the pattern is, for example, 5 or more and 500 or less. The pattern width is, for example, 3 nm or more and 50 nm or less. Such high aspect ratio patterns are prone to collapse.

[0027] 1, the substrate processing apparatus 100 includes an indexer block 110, a processing block 120, and a control unit 90. The processing block 120 is a section that mainly processes the substrate W, and the indexer block 110 is a section that mainly transports the substrate W between the outside of the substrate processing apparatus 100 and the processing block 120.

[0028] The indexer block 110 includes a load port 111 and a first transport part 112. A substrate container (hereinafter referred to as a carrier) C that is carried in from the outside is placed on the load port 111. A plurality of substrates W are accommodated in the carrier C, for example, arranged at intervals from each other in the vertical direction. In the example of Fig. 1, a plurality of load ports 111 are arranged.

[0029] The first transport unit 112 is a transport robot and can take out an unprocessed substrate W from a carrier C placed on each load port 111. The first transport unit 112 can also be called an indexer robot. The first transport unit 112 transports the unprocessed substrate W taken out from the carrier C to the processing block 120. The processing block 120 can process the unprocessed substrate W. The first transport unit 112 can also receive a processed substrate W from the processing block 120 and transport the processed substrate W to a carrier C of the load port 111.

[0030] In the example of FIG. 1, the processing block 120 includes a plurality of processing units 1 and a second transport section 122. The second transport section 122 is a transport robot and can transport the substrate W between the first transport section 112 and the plurality of processing units 1. In the example of FIG. 1, the processing block 120 also includes a placement section 123. The placement section 123 is, for example, a shelf on which a plurality of substrates W can be placed in a vertically aligned state. The first transport section 112 places an unprocessed substrate W on the placement section 123. The second transport section 122 takes out the unprocessed substrate W from the placement section 123 and transports the substrate W to the processing unit 1. The processing unit 1 processes the substrate W. The configuration of the processing unit 1 will be described later. The second transport section 122 takes out the processed substrate W from the processing unit 1 and transports the substrate W to the placement section 123. The first transport section 112 takes out the substrate W from the platform 123 and transports the substrate W to the carrier C of the load port 111 .

[0031] 1, a plurality of (e.g., four) processing units 1 are provided so as to surround the second transport section 122 in a plan view. This second transport section 122 may also be called a center robot. At each position in a plan view, a plurality of processing units 1 may be stacked in the vertical direction. In other words, a plurality of towers TW (four in the figure) each of which is made up of a plurality of processing units 1 stacked in the vertical direction may be provided so as to surround the second transport section 122.

[0032] The control unit 90 performs overall control of the substrate processing apparatus 100. Specifically, the control unit 90 controls the first transport unit 112, the second transport unit 122, and the processing unit 1. FIG. 2 is a block diagram showing an example of the internal configuration of the control unit 90. The control unit 90 is an electronic circuit, and has, for example, a data processing unit 91 and a storage unit 92. In the specific example of FIG. 2, the data processing unit 91 and the storage unit 92 are connected to each other via a bus 93. The data processing unit 91 may be, for example, an arithmetic processing device such as a CPU (Central Processor Unit). The storage unit 92 may have a non-transient storage unit (for example, a ROM (Read Only Memory)) 921 and a temporary storage unit (for example, a RAM (Random Access Memory)) 922. The non-transient storage unit 921 may store, for example, a program that specifies the processing to be executed by the control unit 90. The data processing unit 91 executes this program, so that the control unit 90 can execute the processing specified in the program. Of course, a part or all of the processing executed by the control unit 90 may be executed by hardware such as a dedicated logic circuit.

[0033] <Processing unit overview> Fig. 3 is a vertical cross-sectional view illustrating an example of the configuration of the processing unit 1 according to the first embodiment. It is not necessary that all processing units 1 in the substrate processing apparatus 100 have the configuration illustrated in Fig. 3. It is sufficient that at least one processing unit 1 in the substrate processing apparatus 100 has the configuration illustrated in Fig. 3.

[0034] The processing unit 1 includes a substrate holding section 2 , a discharge section 3 , and a substrate heating section 4 .

[0035] 3, the processing unit 1 is also provided with a chamber 10. The chamber 10 has a box-like shape, and its internal space corresponds to a processing space for processing the substrate W. The chamber 10 is provided with an openable / closable loading / unloading port (not shown). The second transport part 122 loads an unprocessed substrate W into the chamber 10 through the loading / unloading port, and loads a processed substrate W out of the chamber 10 through the loading / unloading port.

[0036] In the example of Fig. 3, a fan filter unit 11 is provided on the ceiling of the chamber 10. The fan filter unit 11 takes in air from outside the chamber 10, purifies it, and sends the purified air into the chamber 10. Operation of the fan filter unit 11 creates a downflow of clean air in the chamber 10. In the example of Fig. 3, the upstream end of an exhaust pipe 13 is connected to the lower part of the side wall of the chamber 10. Gas in the chamber 10 is exhausted to the outside through the exhaust pipe 13.

[0037] The substrate holding unit 2 is provided in the chamber 10, and rotates the substrate W around a rotation axis Q1 while holding the substrate W in a horizontal position. The horizontal position here means that the thickness direction of the substrate W is aligned along the vertical direction. The rotation axis Q1 is an axis that passes through the center of the substrate W and is aligned along the vertical direction. Such a substrate holding unit 2 may also be called a spin chuck.

[0038] Here, the first main surface Wa of the substrate W on which the pattern is formed faces vertically upward. That is, in the example of Fig. 3, the first main surface Wa of the substrate W held by the substrate holding part 2 corresponds to the upper surface. The pattern includes, for example, at least one of a wiring pattern, an insulating pattern, and a semiconductor pattern.

[0039] In the example of FIG. 3, the substrate holding unit 2 includes a spin base 21, chuck pins 22, and a rotation drive unit 23. The spin base 21 has a plate-like shape (for example, a disk shape) and is provided with its thickness direction aligned along the vertical direction. A plurality of chuck pins 22 are provided on the upper surface of the spin base 21. The plurality of chuck pins 22 are provided at equal intervals along the circumferential direction about the rotation axis Q1. The plurality of chuck pins 22 are provided so as to be displaceable between a holding position and a release position, which will be described next. The holding position is a position where the chuck pins 22 abut against the periphery of the substrate W. The plurality of chuck pins 22 hold the substrate W by stopping at the respective holding positions. FIG. 3 shows the chuck pins 22 stopped at the holding position. The release position is a position where each chuck pin 22 is separated from the substrate W. The plurality of chuck pins 22 stop at the respective release positions, whereby the holding of the substrate W by the plurality of chuck pins 22 is released. The substrate holding unit 2 also includes a pin driving unit (not shown) that displaces the chuck pins 22. The pin driving unit includes a driving source such as a motor and an air cylinder, and is controlled by the control unit 90.

[0040] The rotation drive unit 23 includes a shaft 231 and a motor 232. The upper end of the shaft 231 is connected to the lower surface of the spin base 21, and the shaft 231 extends from the lower surface of the spin base 21 along a rotation axis Q1. The motor 232 is controlled by the control unit 90 to rotate the shaft 231 about the rotation axis Q1. As a result, the spin base 21, the chuck pins 22, and the substrate W rotate together about the rotation axis Q1.

[0041] It is not essential that the substrate holding portion 2 has the chuck pin 22. For example, the substrate holding portion 2 may hold the substrate W by a chuck method such as a vacuum chuck, an electrostatic chuck, or a Bernoulli chuck.

[0042] The discharge unit 3 discharges the processing liquid toward the first main surface Wa of the substrate W held by the substrate holding unit 2. As shown in Fig. 3, the discharge unit 3 includes at least one nozzle 30. The nozzle 30 discharges the processing liquid toward the first main surface Wa of the substrate W held by the substrate holding unit 2. In this case, since the first main surface Wa corresponds to the upper surface of the substrate W, the nozzle 30 is provided vertically above the substrate W held by the substrate holding unit 2. The nozzle 30 is, for example, a straight nozzle that discharges the processing liquid in a continuous flow state.

[0043] In the example of FIG. 3, nozzle 30c, nozzle 30w, and nozzle 30i are shown as nozzles 30. In the example of FIG. 3, nozzles 30c, 30w, and 30i extend along the vertical direction. In the example of FIG. 3, nozzle 30c has an outlet 3c formed on the lower surface thereof, nozzle 30w has an outlet 3w formed on the lower surface thereof, and nozzle 30i has an outlet 3i formed on the lower surface thereof. Nozzle 30c ejects a chemical liquid from outlet 3c, nozzle 30w ejects a rinsing liquid from outlet 3w, and nozzle 30i ejects a drying liquid from outlet 3i. The chemical liquid, rinsing liquid, and drying liquid are all examples of processing liquids, and specific examples thereof will be described later.

[0044] The nozzles 30c, 30w, and 30i discharge the processing liquid toward the center of the first main surface Wa of the substrate W held by the substrate holding unit 2. In the example of FIG. 3, the nozzles 30c, 30w, and 30i are adjacent to each other in the horizontal direction and fixed to each other. In the example of FIG. 3, the nozzles 30c, 30w, and 30i are provided inside the facing member 60. The facing member 60 has, for example, a cylindrical shape. The facing member 60 has a hollow shape, and the lower end opening of the hollow portion opens on the lower surface of the facing member 60. The nozzles 30c, 30w, and 30i are provided in the hollow portion of the facing member 60, and the processing liquid discharged from each nozzle 30 flows out from the lower end opening of the facing member 60. In the example of FIG. 3, the facing member 60 is provided at a position vertically facing the center of the substrate W held by the substrate holding unit 2.

[0045] Nozzle 30 is connected to the downstream end of supply pipe 31, and the upstream end of supply pipe 31 is connected to a processing liquid supply source. In the example of Figure 3, supply pipe 31c, supply pipe 31w, and supply pipe 31i are shown as supply pipes 31.

[0046] The downstream end of the supply pipe 31c is connected to the nozzle 30c, and the upstream end of the supply pipe 31c is connected to a chemical supply source. The chemical supply source has a tank (not shown) for storing the chemical, and supplies the chemical to the upstream end of the supply pipe 31c. As the chemical, for example, hydrofluoric nitric acid obtained by mixing hydrofluoric acid, nitric acid, and water, hydrofluoric acid hydrogen peroxide solution (FPM) obtained by mixing hydrofluoric acid, hydrogen peroxide, and water, tetramethylammonium hydroxide (TMAH), a mixture of sulfuric acid and hydrogen peroxide (SPM), ammonia water, a mixture of ammonia, hydrogen peroxide, and water (SC-1), and a mixture of hydrogen chloride, hydrogen peroxide, and water (SC-2) can be used. The chemical does not have to be a mixture, and may be a single liquid. For example, a single liquid such as hydrofluoric acid (HF), hydrogen peroxide, and sulfuric acid can be used as the chemical.

[0047] The downstream end of the supply pipe 31w is connected to the nozzle 30w, and the upstream end of the supply pipe 31w is connected to a rinse liquid supply source. The rinse liquid supply source has a tank (not shown) that stores the rinse liquid, and supplies the rinse liquid to the upstream end of the supply pipe 31w. As the rinse liquid, for example, pure water, carbon dioxide water, or ozone water can be used.

[0048] The downstream end of the supply pipe 31i is connected to the nozzle 30i, and the upstream end of the supply pipe 31i is connected to a drying liquid supply source. The drying liquid supply source has a tank (not shown) that stores the drying liquid, and supplies the drying liquid to the upstream end of the supply pipe 31i. For example, an organic solvent such as isopropyl alcohol can be used as the drying liquid. The surface tension of the drying liquid is lower than the surface tension of other processing liquids (for example, both the surface tension of the chemical liquid and the surface tension of the rinsing liquid). In addition, the volatility of the drying liquid is higher than the volatility of other processing liquids (for example, both the volatility of the chemical liquid and the volatility of the rinsing liquid).

[0049] A supply valve 32 and a flow rate adjustment valve 33 are inserted in the supply pipe 31. In the example of Fig. 3, a supply valve 32c and a flow rate adjustment valve 33c are inserted in the supply pipe 31c, a supply valve 32w and a flow rate adjustment valve 33w are inserted in the supply pipe 31w, and a supply valve 32i and a flow rate adjustment valve 33i are inserted in the supply pipe 31i. The supply valve 32 switches between opening and closing the supply pipe 31. The flow rate adjustment valve 33 adjusts the flow rate of the processing liquid flowing through the supply pipe 31. The flow rate adjustment valve 33 may be a mass flow controller. The supply valve 32 and the flow rate adjustment valve 33 are controlled by a control unit 90.

[0050] The discharge part 3 discharges various types of processing liquids in the order described below toward the first main surface Wa of the substrate W. This allows the processing unit 1 to sequentially perform various types of processing according to the types of processing liquids on the first main surface Wa of the substrate W. Specific processing will be described later.

[0051] 3, the facing member 60 is configured to be able to discharge gas toward a first main surface Wa of the substrate W held by the substrate holding part 2. In the example of Fig. 3, the space in the hollow part of the facing member 60 other than the nozzle 30 functions as a gas flow path 30g. A lower end opening on the lower surface of the facing member 60 corresponds to the discharge port of the gas flow path 30g.

[0052] In the example of FIG. 3, the upper part of the facing member 60 is connected to the downstream end of the supply pipe 31g. In other words, the downstream end of the supply pipe 31g is connected to the gas flow path 30g. The upstream end of the supply pipe 31g is connected to a gas supply source. The gas supply source has a storage section (not shown) for storing an inert gas, and supplies the inert gas to the upstream end of the supply pipe 31g. The inert gas includes at least one of nitrogen gas and a rare gas, for example. The rare gas includes argon gas, for example.

[0053] Supply pipe 31g is provided with supply valve 32g, flow rate adjustment valve 33g, and heater 34g. Supply valve 32g switches supply pipe 31g between open and closed states. Flow rate adjustment valve 33g adjusts the flow rate of the inert gas flowing through supply pipe 31g. Heater 34g heats the inert gas flowing through supply pipe 31g. Heater 34g may be, for example, an electric resistance heater having a heating wire. Supply valve 32g, flow rate adjustment valve 33g, and heater 34g are controlled by controller 90.

[0054] When the supply valve 32g is opened and the heater 34g is operated, a high-temperature inert gas is discharged from the center of the lower surface of the facing member 60 (i.e., the lower end port of the gas flow passage 30g) toward the center of the first main surface Wa of the substrate W. This can promote drying of the substrate W.

[0055] In the example of FIG. 3, the processing unit 1 is provided with a movement drive unit 35. The movement drive unit 35 moves the discharge head including the nozzle 30c, the nozzle 30w, the nozzle 30i, and the opposing member 60 together. Specifically, the movement drive unit 35 moves the discharge head between a processing position and a waiting position, which will be described next. The processing position is a position where the nozzle 30c, the nozzle 30w, and the nozzle 30i discharge the processing liquid toward the first main surface Wa of the substrate W, for example, a position facing the center of the first main surface Wa of the substrate W in the vertical direction. The processing position is also a position where the opposing member 60 discharges the inert gas toward the first main surface Wa of the substrate W. In the example of FIG. 3, the discharge head stopped at the processing position is shown. The waiting position is a position where the nozzle 30c, the nozzle 30w, and the nozzle 30i do not discharge the processing liquid toward the first main surface Wa of the substrate W, for example, a position radially outward from the substrate holder 2. The standby position is also a position where the opposing member 60 does not discharge the inert gas toward the first main surface Wa of the substrate W.

[0056] FIG. 3 shows an example of a specific configuration of the moving drive unit 35. In the example of FIG. 3, the moving drive unit 35 includes an arm 351, a support column 352, and a driving source 353. The support column 352 is provided radially outward from the guard 7 described later, and extends along the vertical direction. The arm 351 extends along the horizontal direction, its tip end is connected to the discharge head, and its base end is connected to the support column 352. The driving source 353 is controlled by the control unit 90, and rotates the support column 352 in forward and reverse directions within a predetermined angle range around the central axis Q2. The driving source 353 includes, for example, a motor. When the support column 352 rotates in forward and reverse directions within a predetermined angle range around the central axis Q2, the discharge head reciprocates along the circumferential direction about the central axis Q2. The support column 352 is installed so that a processing position and a standby position are located on the movement trajectory of the discharge head. The movement drive unit 35 is not necessarily limited to the embodiment shown in FIG. 3, and may include a linear motion mechanism such as a linear motor.

[0057] The substrate heating section 4 heats the second main surface Wb of the substrate W held by the substrate holding section 2. In the example of FIG. 3, the substrate heating section 4 is provided at a position vertically facing the second main surface Wb of the substrate W. In the example of FIG. 3, the second main surface Wb of the substrate W corresponds to the bottom surface, so the substrate heating section 4 is provided directly below the substrate W. The substrate heating section 4 heats at least a portion of the second main surface Wb of the substrate W to a temperature equal to or higher than the boiling point of the drying liquid. The technical significance of this will be described later.

[0058] In the example of FIG. 3, the substrate heating unit 4 includes a nozzle 40. The nozzle 40 ejects a heat medium toward the second main surface Wb of the substrate W. In the example of FIG. 3, the second main surface Wb of the substrate W corresponds to the bottom surface, so the nozzle 40 may also be called a bottom nozzle. In the example of FIG. 3, a through hole is formed in the center of the spin base 21 of the substrate holding unit 2, and the shaft 231 is a hollow shaft. The through hole of the spin base 21 and the hollow part of the shaft 231 are connected in the vertical direction. A part of the nozzle 40 is disposed in the through hole. An ejection port is formed in the upper surface of the nozzle 40, and the ejection port of the nozzle 40 faces the center of the second main surface Wb of the substrate W in the vertical direction. The nozzle 40 ejects a heat medium toward the center of the second main surface Wb of the substrate W.

[0059] The downstream end of a supply pipe 41 is connected to the nozzle 40. The supply pipe 41 extends inside the shaft 231 and penetrates the shaft 231. The upstream end of the supply pipe 41 is connected to a heat medium supply source. The heat medium is a fluid (gas or liquid), and a more specific example is a liquid such as water. The heat medium supply source has, for example, a tank (not shown) that stores the heat medium, and supplies the heat medium to the upstream end of the supply pipe 41.

[0060] In the example of FIG. 3, supply pipe 41 is provided with supply valve 42, flow rate adjustment valve 43, and heater 44. Supply valve 42 switches supply pipe 41 between open and closed states. Flow rate adjustment valve 43 adjusts the flow rate of the heat medium flowing through supply pipe 41. Flow rate adjustment valve 43 may be a mass flow controller. Heater 44 heats the heat medium flowing through supply pipe 41. Heater 44 may be, for example, an electric resistance heater having an electric heating wire. Supply valve 42, flow rate adjustment valve 43, and heater 44 are controlled by control unit 90.

[0061] When the supply valve 42 opens and the heater 44 operates, a high-temperature heat medium is discharged from the nozzle 40 onto the central portion of the second main surface Wb of the substrate W. The heat medium that has landed on the central portion of the second main surface Wb of the substrate W receives centrifugal force accompanying the rotation of the substrate W, flows radially outward along the second main surface Wb, and is scattered outward from the periphery of the substrate W. As the high-temperature heat medium flows along the second main surface Wb of the substrate W, heat is transferred from the heat medium to the substrate W, and the substrate W is heated.

[0062] In the example of FIG. 3, the processing unit 1 is provided with a guard 7 and a guard lifting drive 71. The guard 7 has a cylindrical shape with the rotation axis Q1 as the central axis, and surrounds the substrate holder 2. The guard 7 can receive the processing liquid and heat medium splashed from the periphery of the substrate W. The guard lifting drive 71 raises and lowers the guard 7 between an upper position and a lower position, which will be described below. The upper position is a position where the upper end of the guard 7 is vertically above the substrate W held by the substrate holder 2. When the guard 7 is located at the upper position, it can receive the processing liquid and heat medium splashed from the periphery of the substrate W. The lower position is a position lower than the upper position, for example, a position where the upper end of the guard 7 is vertically below the upper surface of the spin base 21.

[0063] In the example of FIG. 3, multiple guards 7 are provided. The multiple guards 7 are arranged concentrically. The multiple guards 7 may be used differently depending on the type of processing liquid. In the example of FIG. 3, cups 72 corresponding to each guard 7 are provided. The cups 72 have an annular (e.g., annular) recess (groove) surrounding the rotation axis Q1. Each cup 72 receives the processing liquid that has flowed down the inner circumferential surface of the corresponding guard 7. The upstream end of the discharge pipe 12 is connected to, for example, the bottom of each cup 72. The processing liquid received in each cup 72 is discharged to the outside of the processing unit 1 through the discharge pipe 12.

[0064] <An example of the operation of the substrate processing apparatus> Next, an example of the operation of the processing unit 1 will be described. Fig. 4 is a flow chart showing an example of the operation of the processing unit 1. The control unit 90 causes the processing unit 1 to execute processes from step S1 to step S7 according to a preset processing procedure (recipe). Fig. 5 is a diagram showing an example of the state of the processing unit 1 in a drying liquid supplying step described later.

[0065] First, the second transport part 122 transports the substrate W to the processing unit 1. Then, the substrate holding part 2 holds the substrate W received from the second transport part 122 (step S1: holding step). As a specific example, the substrate holding part 2 displaces the multiple chuck pins 22 from their respective release positions to their holding positions. As a result, the multiple chuck pins 22 hold the substrate W. The substrate holding part 2 continues to hold the substrate W until the processing of the substrate W is completed.

[0066] Next, the substrate holding part 2 starts rotating the substrate W (step S2: rotation start step). The substrate holding part 2 may continue rotating the substrate W until the processing of the substrate W is completed.

[0067] Next, the processing unit 1 supplies the chemical liquid to the first main surface Wa of the substrate W (Step S3: Chemical liquid process). First, the movement drive unit 35 moves the discharge head to the processing position. Also, the guard lift drive unit 71 raises the guard 7 for the chemical liquid to the upper position. Then, the control unit 90 opens the supply valve 32c. That is, the control unit 90 switches the supply valve 32c from a closed state to an open state. As a result, the chemical liquid is discharged from the nozzle 30c toward the first main surface Wa of the substrate W during rotation. The chemical liquid that has landed on the first main surface Wa of the substrate W flows radially outward due to the centrifugal force accompanying the rotation of the substrate W, and is scattered from the periphery of the substrate W. At this time, the chemical liquid acts on the first main surface Wa of the substrate W, and a chemical liquid process according to the type of the chemical liquid is performed on the first main surface Wa of the substrate W. For example, the processing unit 1 performs a cleaning process for cleaning and removing impurities on the first main surface Wa of the substrate W, or an etching process for etching a predetermined film on the first main surface Wa of the substrate W. The chemical solution scattered from the periphery of the substrate W is received by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12.

[0068] When the substrate W has been sufficiently processed, the control unit 90 closes the supply valve 32c. As a specific example, the control unit 90 measures the elapsed time from the start of the discharge of the chemical liquid, and determines whether the elapsed time is equal to or longer than a predetermined chemical liquid time. The chemical liquid time is set in advance to a time sufficient for the chemical liquid processing to be performed sufficiently. The elapsed time is measured, for example, by a timer circuit (not shown) belonging to the control unit 90. When the elapsed time is equal to or longer than the chemical liquid time, the control unit 90 switches the supply valve 32c from an open state to a closed state.

[0069] Next, the processing unit 1 supplies a rinse liquid to the first main surface Wa of the substrate W (step S4: rinse step). When the guard 7 for the rinse liquid is different from the guard 7 for the chemical liquid, the guard lifting drive unit 71 appropriately lifts and lowers the guard 7 to place the guard 7 for the rinse liquid in the upper position. Then, the control unit 90 opens the supply valve 32w. That is, the control unit 90 switches the supply valve 32w from a closed state to an open state. As a result, the rinse liquid is discharged from the nozzle 30w toward the first main surface Wa of the substrate W during rotation. The rinse liquid that has landed on the first main surface Wa of the substrate W flows radially outward due to the centrifugal force caused by the rotation of the substrate W, and is scattered from the periphery of the substrate W. At this time, the rinse liquid pushes the chemical liquid on the first main surface Wa of the substrate W radially outward. As a result, the processing liquid on the first main surface Wa of the substrate W is replaced from the chemical liquid to the rinse liquid. The processing liquid splashed from the periphery of the substrate W is received by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12 .

[0070] When the chemical liquid has been sufficiently replaced with the rinsing liquid, the control unit 90 closes the supply valve 32w. As a specific example, the control unit 90 measures the elapsed time from the start of discharge of the rinsing liquid, and switches the supply valve 32w from the open state to the closed state when the elapsed time is equal to or longer than a predetermined rinsing time. The rinsing time is set in advance to a time that allows the chemical liquid to be sufficiently replaced with the rinsing liquid.

[0071] Next, the processing unit 1 supplies a drying liquid to the first main surface Wa of the substrate W (Step S5: drying liquid supplying step). When the guard 7 for the drying liquid is different from the guard 7 for the rinsing liquid, the guard lifting drive unit 71 lifts and lowers the guard 7 appropriately to raise the guard 7 for the drying liquid to the upper position. Then, the control unit 90 opens the supply valve 32i. That is, the control unit 90 switches the supply valve 32i from a closed state to an open state.

[0072] When the supply valve 32i opens, as shown in Fig. 5, the drying liquid is discharged from the discharge port 3i of the nozzle 30i toward the first main surface Wa of the substrate W being rotated. The temperature of the drying liquid may be, for example, room temperature (for example, about 25 degrees Celsius). The temperature of the drying liquid here is, for example, the temperature of the drying liquid at the discharge port 3i. Moreover, the room temperature here includes, for example, the temperature of the drying liquid when a heater for heating the drying liquid is not provided upstream of the discharge port 3i or when the heater is not operating. In other words, the room temperature includes the temperature of the drying liquid that is not heated.

[0073] The drying liquid from the nozzle 30i lands on the center of the first main surface Wa of the substrate W. The drying liquid that has landed on the first main surface Wa flows radially outward due to centrifugal force accompanying the rotation of the substrate W, and splashes off from the periphery of the substrate W. At this time, the drying liquid pushes away the rinsing liquid on the first main surface Wa of the substrate W, so that the processing liquid on the first main surface Wa of the substrate W is replaced from the rinsing liquid to the drying liquid. The processing liquid that has splashed off from the periphery of the substrate W is received by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12.

[0074] Here, the rotation speed of the substrate W in the drying liquid supplying step may be set to, for example, 150 rpm or more and 600 rpm or less, or 200 rpm or more and 400 rpm or less. As a more specific example, the rotation speed may be set to 300 rpm.

[0075] Moreover, the processing unit 1 heats the second main surface Wb of the substrate W when the drying liquid is supplied. That is, the substrate heating section 4 heats the second main surface Wb of the substrate W. As a more specific example, the control section 90 opens the supply valve 42 and activates the heater 44. As a result, as shown in FIG. 5, a high-temperature heat medium (e.g., hot water) is discharged from the nozzle 40 toward the center of the second main surface Wb of the substrate W during rotation. The heat medium that has landed on the center of the second main surface Wb of the substrate W flows radially outward due to the centrifugal force caused by the rotation of the substrate W, and is scattered from the periphery of the substrate W. When the high-temperature heat medium flows along the second main surface Wb of the substrate W, heat is transferred from the heat medium to the substrate W, and the substrate W is heated. The heat of the substrate W is transferred to the drying liquid on the first main surface Wa. As a result, the drying liquid on the first main surface Wa of the substrate W is also heated and the temperature increases.

[0076] The substrate heating unit 4 heats the second main surface Wb of the substrate W so that the temperature of at least a part (here, the center) of the second main surface Wb of the substrate W becomes equal to or higher than the boiling point of the drying liquid. For example, the heater 44 heats the heat medium so that the temperature of the heat medium (hereinafter also referred to as the medium temperature) becomes equal to or higher than the boiling point of the drying liquid. The medium temperature of the heat medium here is, for example, the temperature of the heat medium at the discharge port of the nozzle 40. When the drying liquid is isopropyl alcohol, the boiling point is 82.4 degrees Celsius, and the medium temperature of the heat medium is set to, for example, about 85 degrees Celsius. However, the medium temperature of the heat medium can be set to less than the boiling point of the heat medium. For example, when the heat medium is water, it may be set to less than 90 degrees Celsius, which is 10 degrees lower than the boiling point (100 degrees Celsius). This makes it possible to comply with the SEMI standard.

[0077] The flow rate control valve 43 may adjust the flow rate of the heat medium to, for example, a value greater than the flow rate of the drying liquid. More specifically, the flow rate control valve 43 may adjust the flow rate of the heat medium to 1000 mL / min or more, or to 1500 mL / min or more.

[0078] The nozzle 30i ejects the drying liquid having a lower temperature than the heat medium. Therefore, the low-temperature drying liquid is continuously supplied to the first main surface Wa of the substrate W. Therefore, the low-temperature drying liquid can cool the first main surface Wa of the substrate W. The cooling capacity of the drying liquid increases as the flow rate of the drying liquid increases. Therefore, the flow rate control valve 33i adjusts the flow rate of the drying liquid to a value at which the temperature of the first main surface Wa of the substrate W is lower than the boiling point. For example, the flow rate of the drying liquid is preset to about 100 mL / min or more, more specifically, can be set to 250 mL / min or more.

[0079] As described above, in the drying liquid supply process, the processing unit 1 heats at least a portion of the second main surface Wb of the substrate W to above the boiling point of the drying liquid, while supplying the drying liquid to the first main surface Wa of the substrate W at a flow rate such that the temperature of the first main surface Wa of the substrate W is below the boiling point of the drying liquid.

[0080] When the rinsing liquid is sufficiently replaced with the drying liquid, the processing unit 1 dries the substrate W (step S6: drying step). Specifically, the processing unit 1 measures the elapsed time from the start of the discharge of the drying liquid, and judges whether the elapsed time is equal to or longer than a predetermined drying liquid supply time. The drying liquid supply time is set in advance to a time sufficient for the rinsing liquid to be sufficiently replaced with the drying liquid. The drying liquid supply time is set to, for example, several tens of seconds or more, and as a specific example, may be set to about 40 seconds. Then, when the elapsed time is equal to or longer than the drying liquid supply time, the processing unit 1 dries the substrate W. Specifically, the control unit 90 closes the supply valve 32i. Also, the substrate heating unit 4 stops heating the second main surface Wb of the substrate W.

[0081] Furthermore, the control unit 90 causes the substrate holding unit 2 to increase the rotation speed of the substrate W. For example, the substrate holding unit 2 may rotate the substrate W at a rotation speed of, for example, 800 rpm or more and 2500 rpm or less, or may rotate the substrate W at a rotation speed of 800 rpm or more and 1500 rpm or less. The substrate holding unit 2 may also increase the rotation speed of the substrate W gradually (for example, in steps).

[0082] The processing unit 1 may supply the inert gas toward the center of the first main surface Wa of the substrate W. Specifically, the control unit 90 may open the supply valve 32g and operate the heater 34g. As a result, high-temperature inert gas is discharged toward the center of the first main surface Wa of the substrate W from a gas discharge port (i.e., the lower end port of the gas flow path 30g) at the center of the lower surface of the facing member 60. The inert gas that hits the center of the first main surface Wa of the substrate W flows radially outward along the first main surface Wa. The heater 34g may heat the inert gas to, for example, 60 degrees Celsius or higher, 70 degrees Celsius or higher, or 80 degrees Celsius or higher. The temperature of the inert gas may be, for example, the temperature of the inert gas at the gas discharge port of the gas flow path 30g. The flow rate adjustment valve 33g may adjust the flow rate of the inert gas to, for example, 10 L (liters) / min or higher and 300 L / min or lower.

[0083] When the drying liquid has sufficiently evaporated, the processing unit 1 stops the discharge of the inert gas and stops the rotation of the substrate W. As a specific example, the control unit 90 measures the elapsed time from the stop of the discharge of the drying liquid, and judges whether the measured time is equal to or longer than a predetermined drying time. The drying time is set in advance to a time that allows the substrate W to be sufficiently dried. When the elapsed time is equal to or longer than the drying time, the control unit 90 switches the supply valve 32g from an open state to a closed state, and causes the substrate holder 2 to stop the rotation of the substrate W. In addition, the movement drive unit 35 moves the discharge head to a standby position, and the guard lift drive unit 71 lowers the guard 7 to the lower position.

[0084] Next, the substrate holder 2 releases the substrate W from its hold (step S7: hold releasing step). Then, the second transporter 122 carries the processed substrate W out of the processing unit 1.

[0085] As described above, the processing unit 1 can perform processing on the substrate W. Moreover, in this embodiment, the substrate heating unit 4 heats the substrate W in the drying liquid supply step following the liquid supply step including the chemical liquid step and the rinsing step. FIG. 6 is a schematic diagram showing an example of a timing chart of the processing unit 1, a change in the medium temperature of the heat medium over time, and a change in the temperature of the first main surface Wa of the substrate W over time. Hereinafter, the temperature of the first main surface Wa of the substrate W is also referred to as the substrate temperature. In the example of FIG. 6, the substrate temperatures at different positions in the radial direction of the first main surface Wa of the substrate W are shown as graphs G1 to G5. The graphs G1 to G5 are closer to the rotation axis Q1 as the numbers of the symbols are smaller. That is, the graph G1 shows the substrate temperature at the most central position of the first main surface Wa of the substrate W, and the graph G5 shows the substrate temperature at the most peripheral position of the first main surface Wa of the substrate W.

[0086] In the example of FIG. 6, the control unit 90 switches the supply valve 32i from a closed state to an open state at time t1. As a result, drying liquid starts to be discharged from the nozzle 30i toward the first main surface Wa of the substrate W. At this time t1, the drying liquid supplying step actually starts. Also, the control unit 90 switches the supply valve 42 from a closed state to an open state at, for example, time t1, and operates the heater 44. As a result, a high-temperature heat medium is discharged from the nozzle 40 toward the second main surface Wb of the substrate W, and the substrate W is heated. In the example of FIG. 6, the medium temperature of the heat medium discharged from the nozzle 40 is higher than the boiling point bp of the drying liquid.

[0087] When the heat medium starts to be discharged, the substrate temperature at each position on the first main surface Wa of the substrate W increases over time. The substrate temperature increases at a high rate of increase to a certain extent, and then increases slowly or may converge. As shown in FIG. 6, the substrate temperature at each position on the first main surface Wa of the substrate W is lower than the boiling point bp of the drying liquid. This is because the flow rate control valve 33i adjusts the flow rate of the drying liquid so that the substrate temperature is lower than the boiling point bp of the drying liquid, as described above. In the example of FIG. 6, the heat medium lands on the center of the second main surface Wb of the substrate W, so that the substrate temperature on the first main surface Wa of the substrate W has a temperature distribution described below. That is, as shown in FIG. 6, the substrate temperature is high at the center of the substrate W and decreases toward the radial outside.

[0088] At time t2, which is later than time t1, the control unit 90 switches the supply valve 32i and the supply valve 42 from an open state to a closed state. That is, at time t2, the drying liquid supplying process essentially ends. The substrate temperature at the center of the first main surface Wa at time t2 may be, for example, 70 degrees Celsius or higher, for example, about 80 degrees Celsius. The substrate temperature at the peripheral portion of the first main surface Wa at time t2 may be, for example, 60 degrees Celsius or higher, specifically, about 70 degrees Celsius.

[0089] As described above, the substrate temperature in the drying liquid supplying step is lower than the boiling point bp of the drying liquid. This makes it possible to more reliably suppress boiling of the drying liquid in the drying liquid supplying step. If the drying liquid on the first main surface Wa of the substrate W boils when the drying liquid is supplied, this will result in adhesion of particles to the first main surface Wa. In this embodiment, the boiling of the drying liquid is more reliably suppressed, so that adhesion of particles to the first main surface Wa of the substrate W can be more reliably suppressed.

[0090] Moreover, in the drying liquid supplying step, the temperature of at least a part of the second main surface Wb of the substrate W is equal to or higher than the boiling point bp of the drying liquid. Therefore, in the drying liquid supplying step, the maximum value in the temperature distribution on the first main surface Wa of the substrate W can be brought closer to the boiling point bp. The minimum value in the temperature distribution on the first main surface Wa of the substrate W in the drying liquid supplying step (i.e., the substrate temperature at the peripheral portion of the first main surface Wa) is, for example, 60 degrees Celsius or higher. In other words, the flow rate of the drying liquid can be set so that the substrate temperature at each position on the first main surface Wa of the substrate W is 60 degrees Celsius or higher and lower than the boiling point bp of the drying liquid.

[0091] For this reason, in this embodiment, in the drying liquid supplying step, the temperature of the drying liquid on the first main surface Wa of the substrate W can be brought closer to the boiling point bp. Therefore, in the drying step immediately after the supply of the drying liquid is stopped, the temperature of the drying liquid can be made higher. Therefore, in the drying step, the surface tension of the drying liquid can be further reduced while the evaporation rate of the drying liquid can be further increased. By reducing the surface tension, the collapse rate of the pattern can be effectively reduced. In addition, since the drying liquid can be evaporated in a shorter time, the impulse on the pattern due to the surface tension of the drying liquid during evaporation can also be reduced. This also effectively reduces the collapse rate of the pattern.

[0092] Furthermore, the substrate heating section 4 supplies a heat medium to the second main surface Wb of the substrate W to heat the substrate W. In this manner, the substrate heating section 4 can heat at least a portion of the second main surface Wb of the substrate W to a temperature equal to or higher than the boiling point of the drying liquid with a simple configuration.

[0093] In the above example, the discharge unit 3 discharges the drying liquid at room temperature, but the drying liquid may be discharged at a high temperature. For example, the discharge unit 3 may further include a heater (not shown). The heater is provided in the supply pipe 31i and heats the drying liquid flowing through the supply pipe 31i. The heater is controlled by the control unit 90. The heater heats the drying liquid so that the temperature of the drying liquid is higher than room temperature and lower than the boiling point bp of the drying liquid. For example, the heater may increase the temperature of the drying liquid to 60 degrees Celsius or higher, and as a specific example, may increase the temperature to about 70 degrees Celsius.

[0094] <Second embodiment> It has been found that the pattern collapse rate tends to be higher in the peripheral portion than in the central portion of the first main surface Wa of the substrate W. Therefore, the second embodiment aims to reduce the pattern collapse rate, particularly in the peripheral portion of the first main surface Wa of the substrate W.

[0095] An example of the configuration of the substrate processing apparatus 100 according to the second embodiment is similar to that of the first embodiment. However, the specific configuration of the substrate heating section 4 of the processing unit 1 differs from that of the first embodiment. FIG. 7 is a diagram that illustrates a first example of the substrate heating section 4 according to the second embodiment. FIG. 7 also illustrates the substrate W held by the substrate holding section 2. In the example of FIG. 7, the substrate heating section 4 is provided at a position that faces vertically the peripheral portion of the second main surface Wb of the substrate W held by the substrate holding section 2. The substrate heating section 4 heats the peripheral portion of the second main surface Wb of the substrate W to a temperature equal to or higher than the boiling point bp of the drying liquid.

[0096] FIG. 8 is a diagram illustrating a first example of a configuration of a part of the processing unit 1 according to the second embodiment. In the example of FIG. 8, the substrate heating unit 4 includes an outlet pipe 45 instead of the nozzle 40. The outlet pipe 45 is provided directly below the substrate W held by the substrate holding unit 2. Specifically, the outlet pipe 45 is provided between the substrate W held by the substrate holding unit 2 and the spin base 21. The outlet pipe 45 extends along the radial direction, and its upstream end is connected to the downstream end of the supply pipe 41. The downstream end of the outlet pipe 45 is located radially inward from the chuck pin 22 of the substrate holding unit 2. The outlet pipe 45 has a discharge port 4a formed therein, which faces the peripheral portion of the second main surface Wb of the substrate W in the vertical direction. The heat medium is discharged from the discharge port 4a of the outlet pipe 45, and the heat medium is deposited on the peripheral portion of the second main surface Wb of the substrate W. The heat medium that has landed on the second main surface Wb moves radially outward as the substrate W rotates, and is scattered outward from the periphery of the substrate W. As a result, the substrate heating unit 4 heats the periphery of the second main surface Wb of the substrate W. The distance between the position where the heat medium landed on the second main surface Wb and the rotation axis Q1 may be 60% or more of the radius of the substrate W, 70% or more, 80% or more, or 90% or more.

[0097] As in the first embodiment, the substrate heating section 4 supplies a heat medium having a temperature equal to or higher than the boiling point bp of the drying liquid to the second main surface Wb of the substrate W. The medium temperature of the heat medium is, for example, about 85 degrees Celsius. The substrate heating section 4 can heat the peripheral portion of the second main surface Wb of the substrate W to a temperature equal to or higher than the boiling point bp of the drying liquid. The temperature of the first main surface Wa of the substrate W decreases radially away from the landing position of the heat medium.

[0098] An example of the operation of the processing unit 1 according to the first example of the second embodiment is similar to that in the flowchart of Fig. 4. However, in the second embodiment, in the drying liquid supplying step (step S5), the substrate heating part 4 heats the peripheral part of the second main surface Wb of the substrate W to the boiling point bp of the drying liquid or higher. In other words, the central part of the second main surface Wb of the substrate W is not heated very much.

[0099] Also, similarly to the first embodiment, in the drying liquid supplying step, the processing unit 1 supplies the drying liquid to the first main surface Wa of the substrate W at a flow rate that makes the temperature of the first main surface Wa of the substrate W lower than the boiling point bp of the drying liquid.

[0100] As described above, in the first example of the second embodiment, the substrate heating section 4 heats the peripheral portion of the second main surface Wb of the substrate W, and therefore it is possible to intensively increase the temperature of the peripheral portion of the first main surface Wa of the substrate W. For example, it is possible to increase the substrate temperature at the peripheral portion (liquid landing position) of the first main surface Wa of the substrate W to about 80 degrees Celsius.

[0101] Therefore, in the drying step immediately after the supply of the drying liquid is stopped, the temperature of the drying liquid on the peripheral portion of the first main surface Wa of the substrate W can be made higher. Therefore, in the drying step, the surface tension of the drying liquid on the peripheral portion can be further reduced, while the evaporation rate of the drying liquid on the peripheral portion can be further increased. This makes it possible to effectively reduce the collapse rate of the pattern on the peripheral portion of the first main surface Wa of the substrate W.

[0102] As described above, the pattern collapse rate in the peripheral portion tends to be higher than the pattern collapse rate in the central portion, so by reducing the pattern collapse rate in the peripheral portion, the pattern collapse rate over the entire first main surface Wa of the substrate can be reduced.

[0103] FIG. 9 is a diagram illustrating a second example of the substrate heating unit 4 according to the second embodiment. In FIG. 9, the substrate W held by the substrate holding unit 2 is also illustrated. In the example of FIG. 9, the substrate heating unit 4 includes a peripheral heating unit 4A and a central heating unit 4B. The peripheral heating unit 4A is provided at a position vertically facing the peripheral portion of the second main surface Wb of the substrate W held by the substrate holding unit 2. The peripheral heating unit 4A heats the peripheral portion of the second main surface Wb of the substrate W to a temperature equal to or higher than the boiling point bp of the drying liquid. The central heating unit 4B is provided radially inward from the peripheral heating unit 4A and at a position vertically facing the central portion of the second main surface Wb of the substrate W. The central heating unit 4B heats the central portion of the second main surface Wb of the substrate W. The central heating unit 4B heats the central portion of the second main surface Wb of the substrate W to a temperature lower than that of the peripheral portion of the second main surface Wb, for example.

[0104] 10 is a diagram illustrating a second example of the configuration of a part of the processing unit 1 according to the second embodiment. In the example of FIG. 10, the peripheral heating unit 4A supplies a heat medium to the peripheral portion of the second main surface Wb of the substrate W, and the central heating unit 4B supplies a heat medium to the central portion of the second main surface Wb of the substrate W. The peripheral heating unit 4A and the central heating unit 4B can supply the heat medium at different medium temperatures. In the example of FIG. 10, the peripheral heating unit 4A includes a supply pipe 41A, a supply valve 42A, a flow rate adjustment valve 43A, a heater 44A, and an outlet pipe 45. The supply pipe 41A, the supply valve 42A, the flow rate adjustment valve 43A, and the heater 44A are similar to the supply pipe 41, the supply valve 42, and the heater 44 in FIG. 8, respectively. 10, central heating section 4B includes supply pipe 41B, supply valve 42B, flow rate adjustment valve 43B, heater 44B, and nozzle 40. Supply pipe 41B, supply valve 42B, flow rate adjustment valve 43B, and heater 44B are similar to supply pipe 41, supply valve 42, and heater 44 in Fig. 3, respectively. Parts of supply pipe 41A and supply pipe 41B are provided adjacent to each other in the hollow portion of shaft 231.

[0105] The heater 44A heats the heat medium so that the first medium temperature of the heat medium discharged from the discharge port 4a of the outlet pipe 45 is equal to or higher than the boiling point bp of the drying liquid. The heater 44B heats the heat medium so that the second medium temperature of the heat medium discharged from the discharge port of the nozzle 40 is, for example, lower than the first medium temperature. The first medium temperature may be, for example, about 85 degrees Celsius, and the second medium temperature may be, for example, about 70 degrees Celsius.

[0106] An example of the operation of the processing unit 1 according to the second example of the second embodiment is similar to the flowchart of FIG. 4. However, in the second example of the second embodiment, in the drying liquid supply step (step S5), the substrate heating unit 4 heats the peripheral portion (at least the position where the heat medium is landed) of the second main surface Wb of the substrate W to a temperature higher than the peripheral portion (for example, a temperature lower than the boiling point bp) while heating the central portion of the second main surface Wb of the substrate W to a temperature lower than that of the peripheral portion (for example, a temperature lower than the boiling point bp). Specifically, in the drying liquid supply step, the control unit 90 opens the supply valve 42A and the supply valve 42B. In addition, the heater 44A heats the heat medium so that the first medium temperature of the heat medium is higher than the boiling point bp of the drying liquid, and the heater 44B heats the heat medium in a range in which the second medium temperature of the heat medium is lower than the first medium temperature. The second medium temperature is, for example, lower than the boiling point bp.

[0107] On the other hand, the substrate temperature at the center of the first main surface Wa of the substrate W is, for example, about 70° C., and the substrate temperature at the peripheral portion of the first main surface Wa of the substrate W is, for example, about 80° C. Here, the substrate temperature at the center of the first main surface Wa of the substrate W refers to, for example, the substrate temperature at a position vertically opposed to the position where the heat medium from the nozzle 40 lands, and the substrate temperature at the peripheral portion refers to, for example, the substrate temperature at a position vertically opposed to the position where the heat medium from the outlet pipe 45 lands.

[0108] As described above, in the second example of the second embodiment, the substrate heating section 4 also heats the peripheral portion of the second main surface Wb of the substrate W. As a result, for example, the substrate temperature at the peripheral portion (liquid landing position) of the first main surface Wa of the substrate W can be raised to about 80 degrees Celsius. This makes it possible to reduce the rate of pattern collapse at the peripheral portion of the first main surface Wa of the substrate W.

[0109] In the second example of the second embodiment, the substrate heating section 4 also heats the central portion of the second main surface Wb of the substrate W. However, the substrate temperature in the central portion of the first main surface Wa of the substrate W is lower than that in the peripheral portion. Since the pattern collapse rate in the peripheral portion of the substrate W tends to be low, even if the substrate temperature in the central portion is lower than that in the peripheral portion, the pattern collapse rate in the central portion can be sufficiently reduced. In addition, since the central portion of the substrate W is not excessively heated, the power consumption of the substrate heating section 4 can be reduced. In other words, the processing unit 1 can reduce the pattern collapse rate in the central portion of the first main surface Wa of the substrate W while reducing the power consumption, thereby further reducing the overall pattern collapse rate.

[0110] Furthermore, the substrate heating section 4 supplies the heat medium at the first medium temperature to the peripheral portion of the second main surface Wb of the substrate W, and supplies the heat medium at the second medium temperature to the central portion of the second main surface Wb of the substrate W. Therefore, the processing unit 1 can reduce the collapse rate of the entire pattern on the first main surface Wa of the substrate W with a simple configuration.

[0111] In the above example, the substrate heating section 4 includes the peripheral heating section 4A and the central heating section 4B, but may include three or more heating sections. The three or more heating sections may be arranged side by side in the radial direction. The three or more heating sections heat different parts of the second main surface Wb of the substrate W in the radial direction. In this case, the heating section that is closer to the peripheral section of the substrate W may heat the corresponding part of the second main surface Wb of the substrate W to a higher temperature.

[0112] <Third embodiment> In the first and second embodiments, the substrate heating unit 4 heats the second main surface Wb of the substrate W throughout the entire drying liquid supply time in the drying liquid supplying step (step S5). However, this is not necessarily limited to this.

[0113] FIG. 11 is a diagram showing an example of a timing chart of the processing unit 1 according to the third embodiment. In the example of FIG. 11, at time t1, the control unit 90 switches the supply valve 32i from a closed state to an open state. As a result, the drying liquid starts to be discharged from the nozzle 30i toward the first main surface Wa of the substrate W. That is, the drying liquid supplying process substantially starts at time t1. On the other hand, in the example of FIG. 11, the control unit 90 switches the supply valve 42 from a closed state to an open state at time t12 after time t1. As a result, the high-temperature heat medium starts to be discharged from the nozzle 40 toward the second main surface Wb of the substrate W. That is, the substrate heating unit 4 starts to heat the second main surface Wb of the substrate W. Then, at time t2 after time t12, the control unit 90 switches the supply valve 32i and the supply valve 42 from an open state to a closed state. That is, the drying liquid supplying process substantially ends at time t2.

[0114] As described above, in the third embodiment, during the drying liquid supply time T from time t1 to time t2, the substrate heating unit 4 does not heat the second main surface Wb of the substrate W during a predetermined pre-time T1 from time t1 to time t12, but heats the second main surface Wb of the substrate W during a predetermined post-time T2 from time t12 to time t2. The post-time T2 is set in advance to a time at which the temperature of the first main surface Wa of the substrate W at time t2 sufficiently approaches the boiling point bp of the drying liquid. For example, the post-time T2 may be set to half or less of the drying liquid supply time T, or may be set to one-third or less, one-quarter or less, or one-tenth or less of the drying liquid supply time T.

[0115] As described above, in the third embodiment, the substrate heating section 4 does not heat the substrate W during the previous time T1, and heats the second main surface Wb of the substrate W during the later time T2. That is, the substrate heating section 4 heats the second main surface Wb of the substrate W only during the later time T2. This makes it possible to shorten the operation time of the substrate heating section 4, and reduce the power consumption of the substrate processing apparatus 100. Furthermore, when the substrate heating section 4 supplies a high-temperature heat medium to the second main surface Wb of the substrate W, the amount of heat medium used can be reduced. When the heat medium is liquid, liquid saving can be achieved.

[0116] <Fourth embodiment> In the above example, the processing unit 1 performs the chemical step (step S3), the rinsing step (step S4), the drying liquid supply step (step S5), and the drying step (step S6) in this order, but this is not necessarily limited to this.

[0117] Fig. 12 is a flowchart showing a first example of the operation of the processing unit 1 according to the fourth embodiment. In the example of Fig. 12, the control unit 90 causes the processing unit 1 to execute processes from step S11 to step S19 according to a preset processing procedure (recipe). Steps S11 to S15 are similar to steps S1 to S5, respectively. However, in step S15 (drying liquid supplying step), the substrate heating unit 4 does not have to heat the substrate W.

[0118] Next, the processing unit 1 hydrophobicizes the first main surface Wa of the substrate W (corresponding to step S16: hydrophobization process: liquid supply process). Specifically, the processing unit 1 includes a nozzle that ejects a hydrophobization liquid, and ejects the hydrophobization liquid from the nozzle onto the first main surface Wa of the substrate W during rotation. The hydrophobization liquid includes, for example, a silicon-based hydrophobization liquid. The silicon-based hydrophobization liquid is a hydrophobization liquid that hydrophobicizes silicon (Si) itself and compounds containing silicon. The hydrophobization liquid is, for example, a silylation liquid that includes a liquid silylation agent (also called a silane coupling agent). When the first main surface Wa of the substrate W has been sufficiently hydrophobized, the processing unit 1 stops ejecting the hydrophobization liquid from the nozzle.

[0119] Next, the processing unit 1 executes steps S17 to S19, which are similar to steps S5 to S7, respectively.

[0120] As described above, in the first example described above, the drying liquid supplying step (step S17) is performed in the same manner as the drying liquid supplying step (step S5) in the first to third embodiments. This makes it possible to reduce the collapse rate of the pattern on the substrate W. Moreover, since the first main surface Wa of the substrate W is hydrophobized, the contact angle of the first main surface Wa can be reduced. This makes it possible to reduce the surface tension acting on the pattern, and further reduce the collapse rate of the pattern.

[0121] FIG. 13 is a flowchart showing a second example of the operation of the processing unit 1 according to the fourth embodiment. In the example of FIG. 13, the control unit 90 causes the processing unit 1 to execute the processes from step S21 to step S26 according to a preset processing procedure (recipe). Steps S21 to S26 are the same as steps S1 to S3 and steps S5 to S7, respectively. However, at the end of step S23 (chemical liquid process: equivalent to liquid supplying process), metal is exposed on the first main surface Wa of the substrate W. According to the second example, step S24 (drying liquid supplying process) is performed after step S23. Therefore, water is not supplied to the first main surface Wa of the substrate W. Therefore, it is possible to avoid a reaction between metal and water, and to avoid a defect caused by the reaction. Also, in the above-mentioned second example, the drying liquid supplying process (step S24) is performed in the same manner as the drying liquid supplying process (step S5) in the first to third embodiments. Therefore, it is possible to reduce the collapse rate of the pattern on the substrate W.

[0122] <Fifth embodiment> FIG. 14 is a diagram showing an example of the configuration of the processing unit 1 according to the fifth embodiment. The processing unit 1 according to the fifth embodiment differs from the processing unit 1 according to the first embodiment in the configuration of the discharge unit 3 and the facing member 60. In the example of FIG. 14, the facing member 60 includes a blocking plate 6 and a hollow shaft 61. The blocking plate 6 is provided at a position facing the first main surface Wa of the substrate W held by the substrate holding unit 2 in the vertical direction. In the example of FIG. 14, since the first main surface Wa of the substrate W corresponds to the upper surface, the blocking plate 6 is provided vertically above the substrate W. The blocking plate 6 has, for example, a plate-like shape, and is provided with its thickness direction along the vertical direction. The lower surface of the blocking plate 6 is a facing surface facing the first main surface Wa of the substrate W. The blocking plate 6 has, for example, a circular shape in a plan view. The diameter of the blocking plate 6 (i.e., the diameter of the facing surface) may be, for example, 80% or more of the diameter of the substrate W, or may be 90% or more, or may be equal to or greater than the diameter of the substrate W.

[0123] In the example of FIG. 14, a hollow shaft 61 is provided on the upper surface of the blocking plate 6. The hollow shaft 61 has a hollow portion, and a through hole is formed in the center of the blocking plate 6, passing through the blocking plate 6 in the vertical direction. The hollow portion is connected to the through hole of the blocking plate 6 in the vertical direction. The nozzle 30i is provided in the hollow portion of the hollow shaft 61 and the through hole of the blocking plate 6. The diameter of the outer peripheral surface of the nozzle 30i is smaller than the diameters of the inner peripheral surfaces of the hollow shaft 61 and the blocking plate 6. The space between the outer peripheral surface of the nozzle 30i and the inner peripheral surfaces of the hollow shaft 61 and the blocking plate 6 functions as a gas flow path 30g.

[0124] 14, nozzle 30c and nozzle 30w are provided outside facing member 60. Also, in the example of Fig. 14, movement drive unit 35c and movement drive unit 35w are provided as movement drive unit 35. Movement drive unit 35c moves nozzle 30c between a processing position and a standby position, and movement drive unit 35w moves nozzle 30w between the processing position and the standby position.

[0125] In the example of FIG. 14, a moving drive unit 35i is provided as the moving drive unit 35. The moving drive unit 35i moves the nozzle 30i and the opposing member 60 together. The moving drive unit 35i moves the nozzle 30i and the opposing member 60 together, for example, along the vertical direction. In this case, the moving drive unit 35i can also be said to be an elevation drive unit. The moving drive unit 35i includes a drive source such as a motor, and a power transmission unit that transmits power from the drive source to the nozzle 30i and the blocking plate 6. The power transmission unit includes, for example, a cam mechanism or a ball screw mechanism.

[0126] The operation of the processing unit 1 according to the fifth embodiment is similar to that of the flowchart in Fig. 4. However, the movement driver 35i lowers the nozzle 30i and the opposing member 60 to a processing position closer to the substrate W in the drying liquid supplying step and the drying step, and raises them to a standby position higher than the processing position in other steps.

[0127] In the fifth embodiment, the drying liquid supplying step (step S5) in the first to third embodiments is also performed, so that the collapse rate of the pattern on the peripheral portion of the substrate W can be reduced.

[0128] As described above, the substrate processing apparatus 100 and the substrate processing method have been described in detail, but the above description is merely an example in all respects, and this disclosure is not limited thereto. In addition, the above-mentioned various modified examples can be combined and applied as long as they are not mutually inconsistent. It is understood that many modified examples not exemplified can be envisioned without departing from the scope of this disclosure.

[0129] In the above example, a dedicated nozzle is provided for each fluid, but one nozzle may be shared by different types of fluid.

[0130] In the above example, the substrate heating section 4 supplies a heat medium to the second main surface Wb of the substrate W, but this is not necessarily limited to this. The substrate heating section 4 may include, for example, a heater provided at a position facing the second main surface Wb of the substrate W in the vertical direction. The heater may be, for example, an electric resistance heater including an electric heating wire, or an optical heater that outputs light for heating. For example, the peripheral heating section 4A may be an electric resistance heater or an optical heater. The peripheral heating section 4A may be provided so as to surround the rotation axis Q1. The central heating section 4B may also be an electric resistance heater or an optical heater. [Explanation of symbols]

[0131] bp boiling point S1 Holding process (step) S4, S16, S23 Liquid supply process (step) S5, S17, S24 Drying liquid supply process (step) S6, S18, S25 Drying process (step) T Drying liquid supply time T1 Pre-time Time after T2 W substrate Wa First main surface Wb 2nd principal surface

Claims

1. a holding step of holding a substrate having a first main surface on which a pattern is formed and a second main surface opposite to the first main surface; a liquid supplying step of supplying a processing liquid to the first main surface of the substrate; a drying liquid supplying step of supplying the drying liquid to the first main surface of the substrate at a flow rate such that the temperature of the first main surface of the substrate is lower than the boiling point of the drying liquid while heating at least a part of the second main surface of the substrate to a temperature equal to or higher than the boiling point of the drying liquid after the liquid supplying step; a drying step of drying the substrate after the drying liquid supplying step; A substrate processing method comprising:

2. 2. The substrate processing method according to claim 1, a heating medium having a boiling point equal to or higher than the boiling point of the drying liquid is supplied to the second main surface of the substrate in the drying liquid supplying step.

3. 3. The substrate processing method according to claim 1, further comprising the steps of: a drying liquid supplying step of supplying a drying liquid to the substrate, the drying liquid being supplied to the substrate at a peripheral portion of the second main surface of the substrate, the peripheral portion being heated to a boiling point of the drying liquid or higher.

4. 4. The substrate processing method according to claim 3, a drying liquid supplying step of supplying a drying liquid to a central portion of the second main surface of the substrate, the central portion being heated to a temperature lower than a temperature of the peripheral portion of the second main surface.

5. 5. The substrate processing method according to claim 4, further comprising the steps of: a drying liquid supply step of supplying a heat medium having a first medium temperature to the peripheral portion of the second main surface of the substrate, and a heat medium having a second medium temperature lower than the first medium temperature to the central portion of the second main surface of the substrate.

6. 3. The substrate processing method according to claim 1, further comprising the steps of: a drying liquid supplying step of supplying the drying liquid to the second main surface of the substrate, the second main surface being heated only during a latter period of a drying liquid supplying time during which the drying liquid is supplied.

7. 3. The substrate processing method according to claim 1, further comprising the steps of: A substrate processing method, wherein in the drying liquid supplying step, the temperature of the first main surface of the substrate is equal to or higher than 60 degrees Celsius and lower than the boiling point of the drying liquid.

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